title: An experimental study of endovascular stenting with special reference to the effects on the aortic vasa vasorum.
abstract: OBJECTIVE
  To evaluate the effects of bare stents and covered stents on the aortic wall, especially the vasa vasorum.
  
  
  METHODS
  Eight bare stents and nine covered stents were placed in the infrarenal aorta of nine dogs. The dogs were euthanized at 4-45 weeks after stent placement. The vasa vasorum was evaluated by microstereoscopy with vascular casting, and the histopathology of the aortic wall was examined by light microscopy.
  
  
  RESULTS
  In the unstented normal aorta, vasa vasorum nourished the adventitia and the outer media, and the intima and inner media were avascular. In the stented segment, vascular dilatation and proliferation of vasa vasorum, medial atrophy, and intimal hyperplasia were observed, more prominent for covered stents than for bare stents.
  
  
  CONCLUSIONS
  Intravascular stent placement caused not only medial atrophy and intimal hyperplasia but also proliferation of the vasa vasorum, probably due to hypoxia in the aortic wall.
authors.affiliation: Department of Radiology, Kanazawa University School of Medicine, 13-1 Takara-machi, Kanazawa 920, Japan.
authors.forename: J I
authors.initials: JI
authors.lastname: Sanada
authors.forename: O
authors.initials: O
authors.lastname: Matsui
authors.forename: J
authors.initials: J
authors.lastname: Yoshikawa
authors.forename: T
authors.initials: T
authors.lastname: Matsuoka
mesh_terms: D000818:Animals; D001012:Aorta, Abdominal / Q000166:cytology / Q000601:surgery*; D019917:Blood Vessel Prosthesis Implantation; D002455:Cell Division; D003097:Collateral Circulation; D004285:Dogs; D005500:Follow-Up Studies; D009131:Muscle, Smooth, Vascular / Q000098:blood supply / Q000166:cytology; D015607:Stents; D014651:Vasa Vasorum / Q000166:cytology